An improved plate theory of \(\{1,2\}\)-order for thick composite laminates (Q1210011)

The author developed a two-dimensional laminate plate theory for the linear elastostatic analysis of thick composite plates. He postulated that the inplane displacements are described by linear expansions, and the outplane displacement is described by quadratic ones through the laminate thickness, where the low-order expansion coefficients correspond to the variables of Reissner's first order shear-deformation theory. The theory has been evaluated on the problem of cylindrical bending of an infinite carbon/epoxy laminate subjected to a sinusoidal transverse pressure. The results obtained have been compared with the exact solution of this problem. From the results we see that the plate theory predictions and exact elasticity solutions compare very closely for thin laminates and reasonably well for thick laminates. The major advantage of this theory over the other higher-order theories lies in its perfect suitability for finite element approximations.